1. Field of the Invention
This invention relates to a turning opening or closing member supporting structure in a helmet.
The turning opening or closing member in a helmet is a chin-ventilation in the case of a full-face helmet so as to open or close a ventilation hole and is a shield of a helmet wearing person in the case of both the full-face helmet and a jet-stream type helmet and the like.
The normal turning opening or closing member supporting structure is supported with its single turning center point being applied during its turning operation, and it is opened or closed in such a way that a turning orbit of the opening or closing operation may draw a specified arc.
Due to this fact, as the supporting structure for the shield acting as the aforesaid turning opening or closing member, the applicant had a proposal for a structure in which two separated arc holes are opened, each of the arc holes has two locations of turning center points of the shield so as to cause the turning center points to be switched in sequence during the shield opening or closing operation (refer to Patent Document 1, for example).
2. Related Art
As the related art, there is Gazette of Japanese Patent unexamined publication Hei 11-247018.
At this time, in order to help removing the face shield mist and accumulation of hot air rapidly, efficiency of exchanging air in the helmet should be improved by increasing the volume of introducing outside air. As one of methods therefor, it is thought that the volume of introducing outside air is increased by forming a large ventilating hole.
However, in the case of the chin-ventilation to be fixed to a chin part of the full-face helmet, a size of the chin-ventilation corresponds to a size of the ventilation hole, so that if the chin-ventilation had a supporting form with the aforesaid turning center point being single, for example, as shown in FIGS. 12 and 13, there might be present a possibility that the chin-ventilation 102 sometimes protrudes outside widely from the surface of the chin guard part 101 under the opened state of the chin-ventilation so as to deteriorate a design of the helmet in reference to the supporting position of the chin-ventilation 102.
Accordingly, it may be thought that an angle at the time of opening fully the chin-ventilation is lessened and the volume of protruding is lessened. For such a case, the volume of introducing outside air cannot be increased even if the hole of ventilation is widened.
On the contrary, a method in which the chin-ventilation is opened and closed towards the inside of the helmet can be considered. For this method, the chin-ventilation protrudes widely towards the inside of the helmet, thus a space for the chin-ventilation needs to be kept inside the chin guard portion and such a method cannot be adopted actually from a point of view of operability for opening and closing.
That is to say, it is difficult to set a central point for turning the chin-ventilation enabling the volume of introducing outside air to increase and enabling design and operability to be satisfied.